Update choice_attr.rst.inc

[flip111]

symfony/symfony#24088

[flip111]

Considering putting the callable and propertypath option before the array in the sentence because:

1. nicer flow of the sentence
2. i would personally recommend it over specifying the attributes for each choice.

In hindsight i prefer this

Use this to add additional HTML attributes to each choice. This can be a callable, a property path (just like choice_label_) or an associative array where the keys match the choice keys and the values are the options for each choice.

[flip111]

I have a question which could go into an issue, but since i'm working on this part of the docs anyway i might as well put it here.

if choices are like

    'choices' => array(
        'Yes' => true,
        'No' => false,
        'Maybe' => null,
    ),

What's then $value, $key, $index in the callback? I guess for the first element it's

value -> true
key -> Yes
index -> Yes

What's the purpose of index here? whatever it is, it's not explained in the docs. I can change this part too.

Another question ... also related: is it possible to get the current data here somehow? I like the attribute of one choice to depends on true/false of the other choices, more specifically i want to check if at least 1 is true.

[javiereguiluz]

@HeahDude maybe you can review this proposed change related to forms? Thanks!

[xabbuh]

[...] the attributes for each [...]

[javiereguiluz]

Thanks for this ... and sorry for having taken so long to merge it.